The smallest phototrophic protists (<3 μm) are important primary producers in oligotrophic subtropical gyres - the Earth's largest ecosystems. In order to elucidate how these protists meet their inorganic nutrient requirements we compared phosphate uptake rates of plastidic and aplastidic protists in the phosphate-depleted subtropical and tropical North Atlantic (4-29°N) using ...

Recent studies in the human adenocarcinoma cell line A549 have identified cell growth-dependent equilibrative nucleoside transporter-1 (hENT1) as a modifier of 3'-fluoro-3'-deoxythymidine (FLT) uptake and retention. In the present study, we used the ability to isolate human lymphoblastoid clones deficient in thymidine kinase 1 (TK1) to study how metabolism and ...

Aggregation appears to be a ubiquitous phenomenon among all nanoparticles and its influence in mediating cellular uptake and interactions remain unclear. Here we developed a simple technique to produce transferrin-coated gold nanoparticle aggregates of different sizes and characterized their uptake and toxicity in three different cell lines. While the aggregation ...

Gold nanoshells have shown a great potential for use as agents in a wide variety of biomedical applications, and some of which require the delivery of large numbers of gold nanoshells onto or into the cells. Here, we develop a ready method to enhance the cellular uptake of gold nanoshells ...

In order to better understand nanoparticle uptake and elimination mechanisms, we designed a controlled set of small, highly fluorescent quantum dots (QDs) with nearly identical hydrodynamic size (8-10 nm) but with varied short ligand surface functionalization. The properties of functionalized QDs and their modes of uptake and elimination were investigated ...

Mitochondrial oxidative stress is a contributing factor in the etiology of numerous neuronal disorders. However, the precise mechanism(s) by which mitochondrial reactive oxygen species modify cellular targets to induce neurotoxicity remains unknown. In this study, we determined the role of mitochondrial aconitase (m-aconitase) in neurotoxicity by decreasing its expression. Incubation ...

INTRODUCTION: We have previously reported enhanced cytotoxic effects of both doxorubicin and antisense oligonucleotides using an optimized ultrasound regime of a single 10s exposure in burst-mode (4MHz, 32W/cm(2)(SaTa), 50ms burst period) in both PC3 (prostate cancer) cells and angiogenic Huvec (human umbilical cord endothelial cells). The objective of this study ...

Although the aspect ratio (AR) of engineered nanomaterials (ENMs) is one of the key physicochemical parameters that could determine biological outcome, not much is understood about how AR contributes to shaping biological outcome. By using a mesoporous silica nanoparticle (MSNP) library that has been constructed to cover a range of ...

Titanium dioxide (TiO(2)) nanoparticles (NPs) are massively fabricated and widely used in daily life, and thus potential risk has been posed to human health. However, the mechanism of the interaction between TiO(2) NPs and cells is still unclear. In this study, the interaction of anatase TiO(2) NPs with HaCaT cells ...

Neuronal death has been reported to involve mitochondrial dysfunction and cell cycle reentry. In this report, we used Nerve Growth Factor (NGF)-differentiated PC12 cells to investigate mechanisms linking mitochondrial dysfunction and cell cycle activation during neuronal death induced by NGF withdrawal and/or oxidative stress. We found that loss of survival ...

The plant cell wall is a dynamic and complex structure whose functional integrity is constantly being monitored and maintained during development and interactions with the environment. In response to cell wall damage (CWD), putatively compensatory responses, such as lignin production, are initiated. In this context, lignin deposition could reinforce the ...

The husk surrounding the ear of corn/maize (Zea mays) has widely spaced veins with a number of interveinal mesophyll (M) cells and has been described as operating a partial C(3) photosynthetic pathway, in contrast to its leaves, which use the C(4) photosynthetic pathway. Here, we characterized photosynthesis in maize husk ...

Tania Nessy N Department of Mathematics, University of British Columbia, Vancouver, British Columbia, - - 2011

Cofilin is an important regulator of actin polymerization, cell migration, and chemotaxis. Recent experimental data on mammary carcinoma cells reveal that stimulation by epidermal growth factor (EGF) generates a pool of active cofilin that results in a peak of actin filament barbed ends on the timescale of 1 min. Here, we ...

Hydroxylated and aminated polyaniline nanowire networks were synthesized and used as anode materials to enhance the electrical outputs of microbial fuel cells (MFCs). MFCs with these anodes generated power and current densities as high as 0.28mW cm(-2) (per geometric anode area) and 2.9mA cm(-2), respectively.

Stress induced premature senescence (SIPS) in mammalian cells is an accelerated ageing response and experimentally obtained on treatment of cells with high concentrations of H(2)O(2), albeit at sub-lethal doses, because H(2)O(2) gets depleted by abundant cellular catalase. In the present study diperoxovanadate (DPV) was used as it is known to ...

The esophageal epithelium has sensory properties that enable it to sustain normal barrier function. Transient receptor potential vanilloid 4 (TRPV4) is a Ca(2+)-permeable channel that is activated by extracellular hypotonicity, polyunsaturated fatty acids, phorbol esters and elevated temperature. We found that TRPV4 is expressed in both human esophageal tissue and ...

A glucose-tolerant strain of the cyanobacterium Synechocystis sp. PCC 6803, generally referred to as wild type, produces a hemolysin-like protein (HLP) located on the cell surface. To analyze the function of HLP, we constructed a mutant in which the hlp gene was disrupted. The growth rate of the mutant was ...

Previous work demonstrated that a mixture of NH(4)Cl and KNO(3) as nitrogen source was beneficial to fed-batch Arthrospira (Spirulina) platensis cultivation, in terms of either lower costs or higher cell concentration. On the basis of those results, this study focused on the use of a cheaper nitrogen source mixture, namely ...

Prostaglandin J(2) (PGJ(2) ) family have been reported to show various kinds of biological activities. Considerable progress has been made toward understanding the mechanism of adipogenesis, however, the mechanisms of other actions of PGJ(2) family remain controversial. The 15-deoxy-Δ(12,14) -PGJ(2) (15d-PGJ(2) ) is one of the members of PGJ(2) family, ...

Fuel cells with a PtAu/C anode and a Pr-doped Mn(2)O(3)/C cathode were stacked without using a bipolar plate, and their discharge properties were investigated in a methanol aqueous solution bubbled with air. A three-cell stack exhibited a stack voltage of 2330 mV and a power output of 21 mW.

Many diatoms that inhabit low-nutrient waters of the open ocean live in close association with cyanobacteria. Some of these associations are believed to be mutualistic, where N(2)-fixing cyanobacterial symbionts provide N for the diatoms. Rates of N(2) fixation by symbiotic cyanobacteria and the N transfer to their diatom partners were ...

CdSe quantum dot (QD ) sensitized TiO(2) films have been fabricated using a one-step microwave assisted chemical bath deposition (MACBD) technique and used as photoanodes for quantum dot sensitized solar cells. This technique allows direct and rapid deposition and a good contact between the CdSe and TiO(2) films. The photovoltaic ...

In the mammalian retina, two types of catecholaminergic amacrine cells have been described. Although dopaminergic type 1 cells are well characterized, the physiology of type 2 cells is, so far, unknown. To target type 2 cells specifically, we used a transgenic mouse line that expresses green fluorescent protein under the ...

Determination of cellular ROS (reactive oxygen species) could lead to a better understanding of the clinical consequences of the enhancement in ROS concentration, and assisting in studies of the biological effect of ROS in cells. This work developed an electrochemical approach for measuring the flux of H(2)O(2) (a major ROS ...

The aim of the present study was to evaluate cell cycle regulation by scavenging H(2)O(2) in tumor cells. A significant arrest in the G1 phase of the cell cycle was demonstrated in CH72-T4 carcinoma cells exposed to catalase, associated with a decrease in cyclin D1 and an increase in the ...

Tungsten dioxide (WO(2)) nanorods were synthesized, which showed excellent catalytic activity for the reduction of triiodide to iodide. The dye-sensitized solar cell (DSC) using WO(2) as a counter electrode (CE) reached a high energy conversion efficiency of 7.25%, which can match the performance of the DSC based on a Pt ...

A miniature cell has been designed and constructed to measure gas solubility in crude oils and bitumen. The cell was made of stainless steel with a total internal volume of 1.835 cc and only an oil sample of 0.4 cc was required for one set of measurements at different pressures. ...

To determine whether asymmetrical cell division takes place during growth and differentiation of corneal epithelial cells, we analyzed the expression of some proteins required for the correct execution of the asymmetric division in cultured RCE1-(5T5) cells, which mimic the differentiation of corneal epithelial cells. RT-PCR and immunostaining showed that Par-3, ...

The conjunctiva is a mucous membrane that covers the sclera and lines the inside of the eyelids. Throughout the conjunctiva are goblet cells that secrete mucins to protect the eye. Chronic inflammatory diseases such as allergic conjunctivitis and early dry eye lead to increased goblet cell mucin secretion into tears ...

Fe(3) O(4) nanoparticles embedded in the shells of encapsulated microbubbles could be used therapeutically as in situ drug-delivery vehicles. Bioeffects on liver tumor cells SMMC-7721 due to the excitation of Fe(3) O(4) nanoparticles attached to microbubbles generated by ultrasound (US) are studied in an in vitro setting. The corresponding release ...

The trabecular meshwork (TM) region of the eye is exposed to a constant low-level of oxidative insult. The cumulative damage may be the reason behind age-dependent risk for developing primary open angle glaucoma. Chronic and acute effects of hydrogen peroxide (H(2)O(2)) on TM endothelial cells include changes in viability, protein ...

In this study, it was found that the immobilized inulinase-producing cells of Pichia guilliermondii M-30 could produce 169.3U/ml of inulinase activity while the free cells of the same yeast strain only produced 124.3U/ml of inulinase activity within 48h. When the immobilized inulinase-producing yeast cells were co-cultivated with the free cells ...

Hydrogen production was studied using immobilized green alga Chlorella sp. through a two-stage cyclic process where immobilized cells were first incubated in oxygenic photosynthesis followed by anaerobic incubation for H(2) production in the absence of sulfur. Chlorella sp. used in this study was capable of generating H(2) under immobilized state ...

Using ectoine-excreting strain Halomonas salina DSM 5928(T), we developed a new process for high-efficiency production of ectoine, which involved a combined process of batch fermentation by growing cells and production by resting cells. In the first stage, batch fermentation was carried out using growing cells under optimal fermentation conditions. The ...

Chitosan (CHT) is a natural, non-toxic, and inexpensive compound obtained by partial alkaline deacetylation of chitin, the main component of the exoskeleton of crustaceans and other arthropods. The unique physiological and biological properties of CHT make this polymer useful for a wide range of industries. In agriculture, CHT is used ...

Hydrogen sulfide (H(2)S) has been classified as a third novel gasotransmitter signaling molecule alongside nitric oxide and carbon monoxide. H(2)S rapidly travels through the cell membranes without using any specific receptors/transporters and signaling intracellular proteins. Recently, it has been shown that H(2)S induces DNA damage and alter cell cycle in ...

A microfluidic system to determine hydrogen peroxide (H(2)O(2)) in individual HepG2 cells based on the electrokinetic gated injection was developed for the first time. A home-synthesized fluorescent probe, bis(p-methylbenzenesulfonate)dichlorofluorescein (FS), was employed to label intracellular H(2)O(2) in the intact cells. On a simple cross microchip, multiple single-cell operations, including single ...

In spite of the mounting concerns, current understanding of the extent and mechanisms of phytotoxicity of manufactured nanomaterials remains limited. Here we show that in Arabidopsis thaliana, ultra-small anatase TiO(2) nanoparticles cause reorganization and elimination of microtubules followed by the accelerated and 26S proteasome-dependent degradation of tubulin monomers. Similar to ...

Detection of viable pathogenic bacteria has widespread application in food safety and human health. Antibody-based methods require a growth step which limits time-to-results performance. In this study, we use a mass-change sensitive cantilever biosensor and a probe, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM), that accumulates only in live cells inducing a mass-change ...

We, for the first time, prepared a flexible photoelectrode for CdS/CdSe quantum dot-sensitized solar cells (QDSSCs). A power conversion efficiency of 3.47% was achieved under AM 1.5G illumination for a sandwich type QDSSC consisting of this flexible photoelectrode, Cu(2)S counter electrode and polysulfide electrolyte between the electrodes.

We have previously showed that a phospholipase A(2) isolated from Lachesis muta snake venom and named LM-PLA(2)-I displayed particular biological activities, as hemolysis, inhibition on platelet aggregation, edema induction and myotoxicity. In the present work, we evaluated the effect of LM-PLA(2)-I on the survival of axotomized rat retinal ganglion cells ...

The two cytochromes (cyt) b(558) of acidic nature, one-95-100 kDa and another one, 60-70 kDa were isolated for the first time from the human's lymphosarcoma tissue cells using gel filtration and ion exchange chromatography. These hemoproteins possess NADPH dependent O(2) (-)-producing and ferrihemoglobin-reducing activities. The incubation of neuropeptide PRP-1 (5 μg) with cytochrome ...

In vitro cell culture experiments with primary cells have reported that cell proliferation is retarded in the presence of ambient compared to physiological O₂ levels. Cancer is primarily a disease of aberrant cell proliferation, therefore, studying cancer cells grown under ambient O₂ may be undesirable. To understand better the impact ...

A single-cell assay was developed to measure the activation of phosphoinositide 3-kinase (PI3K) using microanalytical chemical separations and a fluorescently labeled lipid substrate. Phosphatidyl-inositol 4,5 bisphosphate labeled on its acyl chain with Bodipy fluorescein (Bodipy Fl PIP(2)) was utilized as a substrate for both in vitro and cell-based assays. Detection ...

We previously showed that tumor necrosis factor-α (TNF-α) induces the dysregulation of intracellular calcium [Ca(2+)](i) in β-cells by decreasing the levels of the cytoplasmic Ca(2+) binding protein calbindin-D(28k). The purpose of the present study was to test the hypothesis that TNF-α-induced dysregulation of [Ca(2+)](i) in insulin-producing β-cells causes proteolytic degradation ...

Zn(2+) ions are a critical component of cellular machinery. The ion is required for the function of many cell components crucial to survival, such as transcription factors, protein synthetic machinery, metabolic enzymes, hormone packaging, among other roles. In stark contrast to the cells' necessity for a sufficient Zn(2+) supply, an ...

Boronated porphyrins have emerged as promising dual sensitizers for use in both photodynamic therapy (PDT) and boron neutron capture therapy (BNCT), by virtue of their known tumor affinity, low cytotoxicity in dark conditions, and easy synthesis with high boron content. Octa-anionic 5,10,15,20-tetra[3,5-(nido-carboranylmethyl)phenyl] porphyrin (H₂OCP) is a boronated porphyrin having eight ...